Hydraulic press



March 23 1926.

\w.' FERRls HYDRAULIC PREss Filed Macn 24, 19@

K 2 sheetsfsheet 1 INVENToR.

ATTORNEY.

w.. FERRls March 23 1926.

HYDRAULIC PRESS Filed March 24, 1924 2 Sheets-Sheet 2 INVENTOR. )fm/.TERFMR/.s

A ATTORNEY.

40 control'mcchanism for Patented Mu. 23, 1926.

UNITED STATI-:s4 PATENT OFFICE.

WALTER. EEEEIS, vOE MILWAUKEE, WISCONSIN, AssIGNom To THE OILGEAI COM-rANY, OE -MILWAUKEE, WISCONSIN, lA CORPORATION Or WISCONSIN.

HYDRAULIC PRESS.

Application med March 24, 1924. semina. 701,356.

T o all whom 'it may concern.'

Be it known that If, WALTER Fannie, a. citizen of the United States,residing at Milwaukee, in the county of Milwaukee and 6 State ofWisconsin, have invented a certa-in 'new and usefulIm'provement inHydraulic Presses, of which the following is a full,A

clear, concise, and exact description, referencebeing had to theaccompanying dra'w ings, forming a part of this specification.

This invention has to do with hydraulic presses and,- more particularly,with hydraulic drives therefor.

In some types of presses it is necessary, o1 at least highlydesirable,that the press be capable not only of applying a givenpressure to the work but also of maintaining a high pressure thereon foran appreciable period of time. In a riveter, for insta-nce, it i0 isdesirable to maintain thei pressure, which may be several tons, upon therivet until the rivet has set. I have found that a variable speedhydraulic transmission is well adapted for driving presses of thischaracter when due provisionlv is made for maintaining the givenpressure against leakage losses in the system. v

One object of the present invention is the provision of a novelhydraulic transmission having operating characteristics well suited forthe operation of presses of the character referred' to.

Another object is thev provision of a hydraulic transmission for ressesin which :3.5 the main'operating pump'is automatically operable toproduce a given pressure upon thc work and to maintain that pressureagainst leakage losses. l p

Another object is the provision of a novel hydraulic transmissions. l

.Another object is the provision of a riveter having a hydraulictransmission drive so constructed and arranged as to vprovideportability.

Other objects and advantages will appear from the following descri tionof an il1ustrative embodiment of this'invention. In the drawings: A-

Figure 1 is a sectional view of a variable displacement pump constructedin laccord-- ance with the present invention.

Figure 2 is a sectional view of the pump takei substantially on the line2-2 of Figure Figure 3 is a side elevation of a'riveter driven by thepump. Figure 4 is a `horizontal sectional view taken substantially onthe line 4-4 of Fig# ure 1.

Figure 5 is a sectional viewof the ing valve shown in Figure 3.

The pump shown is a varlable-displace.

ment pump of the type shown and 'fully' described in mycopendingapplication, Serial No. 682,056, tiled December 21, 1923, sothat only a brief description thereof will be suf- 'icient for a fullunderstanding of the present invention. This pump comprises a drivingfcage 10 rotatably mounted in spaced bearings and 12, fixed in'a casing13, and drivenby shaft 14 keyed thereto'. A cylinder barrel I5 rotatableupon a pintle 1G is provided with a series of radial cylinder bores 17,each ycontaining a piston 18 reciprocable longitudinally therein. Eachpiston is provided with a crossliead 19 disposed opposite to andparallel with one of a series of tangential reaction plates 2O removablyfixed in the periphery of the driving cage 10. .A set of rollers 21interposed between each crosshead and reaction plate transmits theoperating thrust.' between each piston and reaction plate and permitsfree longitudinal reciprocat-ion of each crosshead relative to thecooperating plate. The pintle 16is rigidly mounted in an arm 22 having asleeve 23 at its lower end journaled upon a shaft 24 fixed in the lowerpart of the casing 13. Up er and lower pairs of passages 25 yand 26 1nthe pintle terminate 1n ports 27 and 28, respectively, formed in theupper and lower surfaces of the pintle and ar-` ranged to register withcylinder ports during rotation of the cylinder barrel. A

i passage 30 in. arm 22 effects communication betweenthe upper pintlepassages 25 and a pair of passages 31 in shaft Similarly,

l Repassage 32 in arm 22 effects communication between ypassages26 and apair of passages 33 in shaft `24. Passages 31 and 33 com- -m'unicatewith the pump dischargeand intake conduits 34 and 35., respectively,associated with that end 36 of the shaft 24 which projects beyond thecasing 13. A conduit 37 vcommunicating with the passage 32 leadsdownwardly into the body of liquid, preferably oil, in the sump l38constituting the base ofthe casing 13.

The pump in this instance is shown operably connected through theconduits 34 and 35 with the powercyllnder 39 of a hydraulic riveter 40.The riveter shown comprises the usual Gframe having a fixed d ie 41 andcoo erat-ing movabledie 42 carried and actuf' ate by a piston 43 in thepowercylinder.

l tween the' opposite ends ofthe bore 48, the lower end of the borecommunicating at all l through as'sage times with the conduit 35 througha passage 51. Ports 52 and 53 adjacent the opposite ends of 1 tha-bore?arev both covered by the heads 45 and- 47 respectively, when the valve.is in theintermediate position shown. These ports, communicate with theconduit 35 54. lConduit 34 communi` `cates wit an intermediate port 55,covered by the head 46 when the valve is in intermediate position. Apassage 56 in the 'head 46 communicates with the passage 50.- VVh'en inthe position shown, passage -56 also com municates with the deliveredbythe con throughl Vpassa A 45 power cylinderl39. The upper and `endsyofthe port so that liquid duit 35and t e operatin iiui'd isthus'returned tothe 'pump wit out entering the ower wer cylindercommuncate rethe va-lveis lowered from the position shown,

fluid enters from'conduit 34 -to thefbo're beu tween the heads 45 and 47and passes through port- 59 and passage`57 to the upper endof' the powercylinder to drive the operating piston-fdownwardly, fluid from the lowerend of the cylinder esca ing throu l1 the ack tozthe'pump The 'reverse.occurs when termediate-position shown, uid from conj duit34 beingdelivered to the lower end of I the cylinder 551and 6 O'and austmg fromthe upper uit 34 is free' to passfvl s- 56, 50 and'51 to theconpassage/58,7 ports 60y and 3, and con uit'35.

end of the cylindertnrough passage 57, ports 59 and 452 and assa'ge 54.The valve 44 is controlled by a and lever 100 pivoted asat 101 upon theriveter and connected through a link 102 with the valve.

The rate of liquid iow in the conduits 34 and 35 is, in this instance,controlled by regulating pump displacement. It will be understood, ofcourse,`that in operation the pump driving cage 10 is driven by theshaft 14 in one direction only, that is, in .a counter clockwisedirection (Fig. 2), and that the ydisplacement of the pump isproportional to the degree of eccentricityr of the axis of rotation X ofthe cylinder barrel 15 with respect to the axis of rotation Y of thedriving cage l10. Thus, when the longitudinal 22 toward the positionshown in Figure 2,

fluid is discharged by the pump through conduit 34 at ai rateproportional to the distance between the axes X and Y.

In the pump shown, the position of the .arm 22 is controlled by a r'od61 .threaded in a trunnioned nut 62 connected .by appropriate linkage 63'with an upstanding projection 64 carried bythe up er end vof the arm22.

This rod extends ongitudinally within a axis of the pintle 16 iscoincident with the springhousing 65 mounted in and projecting from thecasin 13. :A heavy compression spring 66 within the housing and bearingu on a thrust. collar 67 adjustably the rod and consequently the arm 22in the extreme left position s own in Figure 2. Movement of the rod 61toward the left 'is limited by a Abearingf washer 68v within thevextended end.' @ofthe-housing 65 .and carried-.by a long screwthreadedin the rod The rod 61 is, in this instance, vplaced un- 1 derthe control ofthe working pressure' iny L the'conduit 34.' .I n' themechams'mzjshown I this is accomplished-'bythe provision'ofgfan'extension'71 on'therodl constituting 'a'pis-` j j .ten closely fittedinthe cylinder `lx'ire72ggi'n 1.a block'73zfixedgto; thef'outsideeff-'theI-mair'r casing 13,'. A length-of small bore t' ubing74 fcommunicates at one end withthe' cylinder if bore-72 andsat the'Other'lendiwitha casing communication between the conduit 34 anda portv78gin the easing 75 controlled 4by the yalve 76.- Ihevalvepermits afree How of-iluid through the port 78 fromv 'ipe 77" 'to tube74 .butautomatically -cleses t e port against passage .of -fluid lintheopposite oke coil 7 9. of small' bore tubing. Before beginning ariveting operation, t

Pump Pint-1 16151. the extreme offset 'Y tion shown in Figure 2, andVthe valve 44 is Aio - the die and woi'k is transmitted to the fluidv inthe upper end of -the cylinder and conse-l quently to the boie 72through the conduit 34, pipe 77 lvalve casing inthe intermediateposition shown in Figure 5. Under these conditions, the pump, rotating'in a clockwise direction, is working at full capacity and deliveringfluid through conduit 34 to the valve 44, thefiuid returning from thevalve to the pump through conduit 35 without entering the power cylinder39. To initiate a' working stroke the valve 44 is lowered bymanipulation of the handle 10() to thereby open conin'iunication betweenconduit 34 andthe upper vend of the power cylinder and between thelower'end ot the power cylinder and the conduit 35. This causes a downwardtravel of the piston and die 42 toward the work until engaged andresisted by the work.- The pressure between 75 and tubing 74. Thispressure in the bore 72 acting upon the end of piston 71 causes the rod61 to move toward the right (Fig. 2) against the pres-` sure of thespring 66, to thereby shift the pump pintle 16 toward neutral positionto reduce the stroke'of .the pump. Then'pump stroke is thus reduced inaccordance with the degree of pressure in 'thecondu'it- 34 andin theupper end of the power cylinder, which in turn is dependent upon thepressure between the die 42l and work. Thus, when a y travel.

quences of too sudden a readjustment ofthe a very shoit u ntil theyreach the upper end of the stroke maximum working pressure has been attained and the die'can no longer advance, the pump serves merelyl tomaintain this pressure against leakage losses, the stroke of the pumphaving been reduced to this point by the pressurein the bore 72. i

.When this set pressure has been maintained for a suiicient period, theoperator p shifts-the valve 44 into its upperextreme'pm.

siti'on lto thereby open .communication between the upper end of thepower cylinder and the conduit 35i-and between the lower .end of thecylinder and conduit 34. This instantly relieves the pressure in theconduit 34 and the piston and die begins its upward The check valve 76then comes into play to prevent a' sudden release let' pressure thebore7 2, to thereby prevent the conse.

rod.61 and pump to the'in'aximum stroke po; sitioirof Figure 2. Thisvalve closes the port' 78 so as to prevent the return iowfof fluid fromvexcept through vthe restricted tubing 79. In interval of time, however,the rod 61 and pump pintle 16 arel returned to the position sh'own inFigure 2 and the pis.

ton and die 42 continue their upward travel er until the operatorreturns the control valve 44 to the neutral position of Figure 5. Thetubing 74 is of suiiiciently small di-l ameter and of suiicient lengthf0- dampen v advance said the'tiibing 74 to`the .tubing 77,'

hydraulic means for reducing pump out the periodic pressureiiuctuati'ons that would otherwise occur inthe bore 72, as a result ofthe slight l volume of fluid delivery characteristic oty pumps of themultiple piston type.

As the die engages the work the pressure periodic fluctuations in inthehydraulic circuit ordinarily increases.-

in an interval of time much shorter than is required to effect theautomatic reduction in bodiment of the invention hereinabove spe--citically described, Without departing from pr sacrificing any ot theadvantages of the invention as defined in the appended claims I claim:

1. In a hydraulic press the combination of a plunger, and hydraulicmeans for operat-l ing Vsaid plunger, comprising a variable displacementpump automatically operable to lunger at a .predetermined rate and tomaintain a predetermined pressure between .said plunger and work against2. n a hydraulic press the coiinbinatioii 1100.

of a plunger, hydraulic means including a variable displacement pump foroperating said plunger, and pump displacement regulating meansautomatically operable to maintain aV predeterminedpressure between saidlunger and'workagainst leakage losses. 1-

3. In a hydraulic ress -thecombination of a plunger, hydrau ic -m'eans.including a variable displacement pump for operating "said plunger,means normallyopcrable to yieldably maintain .pump displacementat.

sponsive' vto' sure-betweenl said plunger and workjagainst p leakelos'ses y A4. a hydraulic variable displacement pump `foi 'operatingsaid plunger, means for regulating-'pump displacement, yieldable .meansoperable means responsive to ,iiuid pressure in said 5.In a hydraulicpress the combination cfa plunger, a piston andcylinder for drivingsaid' plunger, a variabledisplacemeni pump for supplying driving iiud'to -sa'id ressj the. combination of a plunger, hydrau ic meansincluding' a -v izo thereon to increase pump displacement, and

cylinder, means responsive to the pressure between said plunger and workfor reducing Vpump displacement, and a Vcontrol valve betweensaid pumpand cylinder for controlling the supply of driving fluid thereto.

said connections for controlling the delivery of fluid to said cylinder.

7. A device of the character described comprising a hydraulic powercylinder, a variable displacement pump, pipe connections between saidpump and cylinder, means responsive to an increase in pressure in saidconnections for decreasing pump dis lacement, and a valve'associatedwith sai connections for controlling the delivery of fluid to said clinder.A

8. A evice of the character described comprising a hydraulic powercylinder, a variable displacement pump, fluid connections including acontrol valve between said pump and cylinder, ,and means for auto- 30matically decreasing pump displacement with an increase of ressure insaid connections so as to esta lish and maintain a predeterminedpressure in said connections against leakage losses.

displacement pump, fluid connections between said pump and motor,.a highpressure relief valve associated with said connections, 40"yieldablemeans for increasingpump dislacement, and means responsive to thepressure in said connections for decreasing pump displacement to therebyestablish andl maintain a predetermined pressure in said connectionsagainst leakage losses. l

10.'A device of the character described comprising a hydraulic motor, avariable displacementpump for supplying `driving lHuid to said motor,means for regulating pump displacement, a spring normally operablethereon to increase pump displacement v to a predetermined maximum,pressure actuated inea-ns operable upon said regulating means to reducepump displacement and a high vpressure relief valve automaticallyoperable to prevent excessive pressures dur.- iiig the operation .ofsaid pressureactuatedI means. Y 11. A device of the character described60l comprising a hydraulic motor, a variable displacement Apump forsupplying fluid to fsaid motor, pressure controlled means for reduin""pump displacement, yieidabie meansj 0r increasing pump displacement,

9. A device of the character described comprising a hydraulic motor, avariable lwork for operating said regulating means to responsive meansautomatically operable to* and means for checking theaction of said l5last named means.

12. A device of the character described comprising a hydraulic motor, avariable displacement pum for supplying fluidl to;

saidv motor, yielda le means for increasing pump displacement, hydraulicmeans controlled by the pressure of fluid delivered' by said pump forreducing pump displacement, and a check valve forchecking the actipnof i'said y-ieldable means but permitting inire- 75 stiicted action of saidhydraulic means.v

13. A device of the character described comprising a variabledisplacement pump, yieldable means for increasing pump displacement,means for decreasing pump. dis.-

placement, and means for checking the and hydraulic means responsiveto-the pressure of Huid delivered by vsaid pump .for vvarying pumpdisplacement, said means including a length of small bore tubingoperable to dampen the eifect of periodic fluctuations in said pressureupon 'said displacement varying means.

17. In a hydraulic press the combination of a plunger, a piston andcylinder for actu- ,105

4ating said plunger, a variable displacement pump directly connectedwith saidcylinder for delivering a driving liquid thereto, means forregulating pumpdisplacement, means for yieldably maintaining'said`regulating means in one 'position to eiect `movement of said plungertoward the work at a Apredetermined rate, and means `responsive to thepressure between said plunger and reduce pumpdisplacement and to therebymaintain a predetermined pressure between the plunger land work againstleakage lossesg.

18. In a hydraulic press the combinatioit of a pluri er, a piston andcylinder for actual.: ating sai plunger, a variable di iplacement pumpfor delivering a driving liquid to saidH f cylinder to operate saidplunger, pressure regulatel pump displacement to maintain the 1725;

pressure substantially constant when said#` I plungeris under load, andhigh pressure` relief mechanism supplementing the action y of` saidregulating'means to avoid sudden excessive pressures. l

19. Inra hydraulic press the combination of a variable displacement ump,a lunger driven by liquid delivered om sai rocate toward and vfrom thepiece of wor Pump" atea rate corresponding to pump d1spla'ce meansAresponsive to the pressure between said plunger and work forreducing-pump 10` displacement tol effect and maintain a 4predeterminedpressure between ysaid plunger and work 'against leakage losses.

Inv witness whereof, I hereunto subscribe of February, 1924.

my name this 1st da 1 l ALTER FERRIS.

